• Title/Summary/Keyword: XPath Query

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A XML Instance Repository Model based on the Edge-Labeled Graph (Edge-Labeled 그래프 기반의 XML 인스턴스 저장 모델)

  • Kim Jeong-Hee;Kwak Ho-Young
    • Journal of Internet Computing and Services
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    • v.4 no.6
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    • pp.33-42
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    • 2003
  • A XML Instance repository model based on the Edge-Labeled Graph is suggested for storing the XML instance in Relational Databases, This repository model represents the XML instance as a data graph based on the Edge-Labeled Graph, extracts the defined value based on the structure of data path, element, attribute, and table index table presented as database schema, and stores these values using the Mapper module, In order to support querry, XML repository model offers the module translating XQL which is a query language under XPATH to SQL, and has DBtoXML generator module restoring the stored XML instance. As a result, it is possible to represent the storage relationship between the XML instances and the proposed repository model in terms of Graph-based Path, and it shows the possibility of easy search of specific element and attribute information.

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XML Repository Model based on the Edge-Labeled Graph (Edge-Labeled Graph를 적용한 XML 저장 모델)

  • 김정희;곽호영
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.5
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    • pp.993-1001
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    • 2003
  • A RDB Storage Model based on the Edge-Labeled Graph is suggested for store the XML instance in Relational Databases(RDB). The XML instance being stored is represented by Data Graph based on the Edge-Labeled Graph. Data Path Table, Element, Attribute, and Table Index Table values are extracted. Then Database Schema is defined, and the extracted values are stored using the Mapper. In order to support querry, Repository Model offers the translator translating XQL which is used as query language under XPATH, into SQL. In addition, it creates DBtoXML generator restoring the stored XML instance. As a result, storage relationship between the XML instance and proposed model structure can be expressed in terms of Graph-based Path, and it shows the possibility of easy search of random Element and Attribute information.

Design and Implementation of Distributed XQuery Query Processor using Distributed ORDBMSs (분산 객체 관계 데이터베이스 시스템을 이용한 분산 XQuery 질의 처리기 설계 및 구현)

  • Lee, Jae-Min;Jang, Gun-Up;Hong, Eui-Kyeong
    • Proceedings of the Korean Information Science Society Conference
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    • 2007.10c
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    • pp.55-59
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    • 2007
  • 최근 컴퓨팅 환경은 인터넷 환경의 웹을 기반으로 한 분산 컴퓨팅 환경으로 변화하고 있다. 그에 따라 XML 문서의 사용과 XML 문서의 양이 급속하게 증가하였으며, 언제나 쉽게 필요한 XML 문서에 접근할 수 있어야 한다. 또한 다양한 형태로 분산 저장된 XML 문서에서 원하는 데이터를 추출하고 변환하며, 단편화된 XML 데이터를 통합하는 작업들이 필요하게 된다. 따라서 XML 문서를 분산 객체 관계 데이터베이스 시스템에 효율적으로 저장하는 시스템을 개발하고, 분산 저장된 XML 문서에서 사용자가 필요한 정보를 검색할 수 있도록 하기 위해 XQuery 질의어를 지원하는 연구가 필요하다. 본 논문에서는 분산 객체 관계 데이터베이스 시스템에 저장된 XML 데이터를 접근할 수 있도록 하기 위해 XPath를 분산 SQL로 변환하여 실행하는 분산 XPath 의 처리기를 확장하여 XQuery를 분산 SQL로 변환하여 실행하는 분산 XQuery 질의 처리기를 설계 및 구현하였다.

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Segment-Based Inverted Index for Querying Large XML Documents (대용량 XML 문서의 효율적인 질의 처리를 위한 세그먼트 기반 역 인덱스)

  • Jeong, Byeong-Soo;Lee, Hiye-Ja
    • Journal of Information Technology Services
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    • v.7 no.3
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    • pp.145-157
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    • 2008
  • The existing XML storage methods which use relational data model, usually store path information for every node type including literal contents in order to keep the structural information of XML documents. Such path information is usually maintained by an inverted index to efficiently process XPath queries for large XML documents. In this study, We propose an improved approach that retrieve information from the large volume of XML documents stored in a relational database, while using a segment-based inverted index for path searches. Our new approach can reduce the number of searching an inverted index for getting target path information. We show the effectiveness of this approach through several experiments that compare XPath query performance with the existing methods.

Implementation of XML Query Processing System Using the Materialized View Cache-Answerability (실체뷰 캐쉬 기법을 이용한 XML 질의 처리 시스템의 구현)

  • Moon, Chan-Ho;Park, Jung-Kee;Kang, Hyun-Chul
    • The KIPS Transactions:PartD
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    • v.11D no.2
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    • pp.293-304
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    • 2004
  • Recently, caching for the database-backed web applications has received much attention. The results of frequent queries could be cached for repeated reuse or for efficient processing of the relevant queries. Since the emergence of XML as a standard for data exchange on the web, today's web applications are to retrieve information from the remote XML sources across the network, and thus it is desirable to maintain the XML query results in the cache for the web applications. In this paper, we describe implementation of an XML query processing system that supports cache-answerability of XML queries, and evaluate its performance. XML path expression, which is one of the core features of XML query languages including XQuery, XPath, and XQL was considered as the XML query. Their result is maintained as an XML materialized view in the XML cache. The algorithms to rewrite the given XML path expression using its relevant materialized view proposed in [13] were implemented with RDBMS as XML store. The major issues of implementation are described in detail. The results of performance experiments conducted with the implemented system showed effectiveness of cache-answerability of XML queries. Comparison with previous research in terms of performance is also Provided.

EP2 Labeling Scheme for XML Data (XML 데이타를 위한 EP2 레이블링 스킴)

  • 진주용;배진욱;이석호
    • Proceedings of the Korean Information Science Society Conference
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    • 2004.10b
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    • pp.79-81
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    • 2004
  • 범위 기반 레이블링 스킴(range-based labeling scheme)을 이용하면 임의의 두 노드에 대한 조상-자손 관계를 쉽게 판별할 수 있으므로, XPath나 XQuery 형태의 질의를 효율적으로 처리할 수 있다. 그러나 노드의 삽입이 일어나는 동적인 상황에서는 불가피하게 전체 또는 일부의 레이블을 다시 할당(re-labeling)할 가능성이 있다는 문제점이 있다. 본 논문에서는 Dietz 레이블링 스킴을 개선한 EP2(extended preorder & postorder) 레이블링 스킴을 제안한다. 제안하는 스킴은 동일한 저장 공간상에서 범위 기반 레이블링 스킴에 비해 동적인 갱신에 유리하며, 기존의 구조 조인 알고리즘(structural join algorithm)을 이용하여 효율적으로 구조 질의(structural query)를 처리할 수 있다.

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XML Document Selection and Query Expansion Modules (XML 문서선별과 질의확장을 위한 자동화 모듈 개발)

  • 김명숙;권혁돈;공용해
    • Proceedings of the Korea Multimedia Society Conference
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    • 2004.05a
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    • pp.455-458
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    • 2004
  • 본 연구는 다양한 형식을 가지는 XML 문서의 효율적인 정보검색을 위한 다음과 같은 자동화 모듈들을 개발하였다 구현된 모듈은 XML 문서를 획득하는 문서추출 모듈, 온톨로지를 이용한 포괄적 DTD 생성 모듈 생성된 포괄적 DTD와 XML 파서를 이용하여 정보검색 대상 XML 문서를 사전에 선별하는 문서여과 모듈, XML 질의를 확장하는 질의확장 모듈, JDOM의 XPath를 이용한 질의엔진 모듈로 구성된다. 이와 같이 구현한 모듈들을 샘플 XML 문서에 적용하여 XML 문서추출, DTD 생성, 문서여과, 질의확장, 질의엔진의 효과를 실험하였다.

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XSTAR: XQuery to SQL Translation Algorithms on RDBMS (XSTAR: XML 질의의 SQL 변환 알고리즘)

  • Hong, Dong-Kweon;Jung, Min-Kyoung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.17 no.3
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    • pp.430-433
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    • 2007
  • There have been several researches to manipulate XML Queries efficiently since XML has been accepted in many areas. Among the many of the researches majority of them adopt relational databases as underlying systems because relational model which is used the most widely for managing large data efficiently. In this paper we develop XQuery to SQL Translation Algorithms called XSTAR that can efficiently handle XPath, XQuery FLWORs with nested iteration expressions, element constructors and keywords retrieval on relational database as well as constructing XML fragments from the transformed SQL results. The entire algorithms mentioned in XSTAR have been implemented as the XQuery processor engine in XML management system, XPERT, and we can test and confirm it's prototype from "http ://dblab.kmu.ac.kr/project.jsp".

The Application and Integration of an Improvement Technique for Layers of NETCONF (NETCONF 계층에 대한 개선 기법 적용 및 통합)

  • Lee, YangMin;Lee, JaeKee
    • Journal of KIISE
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    • v.43 no.2
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    • pp.256-268
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    • 2016
  • Modern networks consisting of various heterogeneous equipment are often installed in a distributed manner. Thus the NETCONF standard was established to manage networks centrally and efficiently. In this paper, we present a method that integrates each NETCONF layer into a single system based on the results of previous studies. In the RPC Layer, an asynchronous communication channel and parallel processes are possible using multi-threading. In the Operation Layer, operational efficiency is increased by using a data group with dependencies between the equipment configuration data and by improving the data structure, enabling efficiently processing of XML queries even with multiple managers. The data modeling techniques and grouping methods in the Content Layer are presented in detail for interoperability between the Operation Layer and the Content Layer. Finally, the GUI program was implemented and its implementation is reported. We performed an experiment comparing the improved NETCONF with the standard NETCONF to measure factors, such as query processing ratio, query processing speed, and CPU utilization. The improved NETCONF demonstrated excellent query processing ratio and query processing speed, whereas the standard NETCONF had excellent CPU utilization.

Query Processing using Information of Parent Nodes in Partitioned Inverted Index Tables (분할된 역 인덱스 테이블에서 부모노드의 정보를 이용한 질의 처리)

  • Kim, Myung-Soo;Hwang, Byung-Yeon
    • Journal of Korea Multimedia Society
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    • v.11 no.7
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    • pp.905-913
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    • 2008
  • Many heterogeneous XML documents are being widely used with the increasing employment of XML, and the importance of data structure research for more efficient document management has been growing steadily. We propose a query processing technique which uses parent node information in a partitioned inverted index tree. The searching efficiency of these heterogeneous documents is greatly influenced by the number of query processing and the amount of target data sets in many ways. Therefore, considering these two factors is very important for designing a data structure. First, our technique stores parent node's information in an inverted index table. Then using this information, we can reduce the number of query processing by half. Also, the amount of target data sets can be lessoned by using partitioned inverted index table. Some XML documents collected from the Internet will be used to demonstrate the new method, and its high efficiency will be compared with some of the existing searching methods.

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